MINSK, Belarus — The government sent busloads of riot police into central Minsk today as the opposition protested President Alexander Lukashenko's overwhelming re-election, and the United States and Europe threatened sanctions over the vote they said was fraudulent.

Only about 5,000 demonstrators showed up — about half the number that had come after the polls closed Sunday night for a protest whose size was extraordinary in the tightly controlled country where police have cracked down swiftly on unsanctioned opposition gatherings.

Lukashenko, who has ruled Belarus with an iron fist since 1994, declared that his foes had failed to topple him in a foreign-backed "revolution."

Russian President Vladimir Putin congratulated Lukashenko and said the outcome would strengthen their alliance. He said in a telegram to Lukashenko that the vote "highlighted voters' trust in your course aimed at strengthening welfare of the Belarusian people," according to the Kremlin.

International observers described the vote as falling short of democratic standards, Europe's main human rights organization deemed it a "farce" and Washington called for a new election.

"The United States does not accept the results of the election," White House spokesman Scott McClellan said, adding that the vote was flawed by "a climate of fear."

Underlying the election is a struggle for regional influence between Russia and the West, which is seen by Lukashenko's government and its backers in Moscow as a major culprit in the political upheaval in former Soviet republics of Ukraine, Georgia and Kyrgyzstan.

Today's smaller crowd could indicate that the opposition is unable to get critical momentum to force through its call for an election rerun. But Milinkevich called on the demonstrators to gird for a lengthy campaign.

"Our protest will be long and strong," he vowed. "We will never recognize this election. It's not an election by an anti-constitutional seizure of power."

As the rally was about to begin, the riot police streamed into Karl Marx Street near Oktyabrskaya Square. Security forces in helmets and camouflage uniforms jogged into neighborhood courtyards and prevented pedestrians from walking toward the square.

The show of strength was in sharp contrast to the previous evening, when police had only a small, unobtrusive presence at the rally, estimated at about 10,000 people.

The protesters had jammed the square shouting "Freedom!" and Milinkevich's name — echoing the much larger crowds in Ukraine's 2004 Orange Revolution, which turned that nation toward the West.

At the square today, a 45-year-old woman who gave her name only as Irina said she was scared about the prospect of bloody police action, but "if Lukashenko stays in power, it will be even worse."

At a boastful and belligerent nationally televised news conference where he repeatedly criticized the United States, Lukashenko repeated allegations that the opposition was backed by Western forces plotting to bring him down.

"The revolution that was talked about so much ... has failed," he said, adding that Belarusians had resisted "colossal pressure from outside" and "showed who's the boss."

"You have seen our opposition, and if you are reasonable people you have been convinced that it's worthless," said the 51-year-old leader who has ruled since 1994.

Lukashenko said the protest leaders were in the pay of Western ambassadors and said there was no crackdown because the opposition is weak.

"Who was there to fight with? Nobody, understand? That's why we gave them the opportunity to show themselves, even though it was illegal," he said of Sunday night's rally.

Milinkevich called the official vote tally for Lukashenko "monstrously inflated" and denounced the leader as an "illegal, illegitimate president."

"In Belarus, we did not have an election but an unconstitutional seizure of power," he said, repeating his demand for a revote "in which he law of the country is followed."

Monitors from the Organization for Security and Cooperation in Europe and the Council of Europe said the Sunday's election was neither free nor fair.

The mission said "arbitrary use of state power and widespread detentions showed a disregard for the basic rights of freedom of assembly, association and expression, and raise doubts regarding the authorities' willingness to tolerate political competition."

The European Union said the elections were marred by intimidation, and the 25-nation bloc likely will impose financial and diplomatic sanctions on Belarus' top political leaders. McClellan also said penalties such as travel restrictions "are things we will look at."

"In a country in which freedom of expression and association are so thoroughly and aggressively suppressed, a vote is not an exercise in democracy, it is a farce," said Terry Davis, president of the Council of Europe, the continent's premier human rights organization.

EU External Relations Commissioner Benita Ferrero-Waldner said "some action is now very likely," including a visa travel ban on top government leaders in Minsk. EU foreign ministers also are considering expanding a freeze on the assets of top Belarus officials, Ferrero-Waldner said.

The Soviet past is strongly palpable in Belarus. The government makes five-year plans, the main state newspaper has "Soviet" in its title and the state security service is still officially called the KGB. Russia, which has an agreement with Belarus envisaging close political, economic and military ties, has staunchly backed Lukashenko, who has become a pariah in the West for his relentless crackdown on opposition and independent media.

Western countries have forged close ties with the opposition and made no secret of their contempt for the ruler of what Washington calls an outpost of tyranny in Europe.

While Lukashenko is a dictator to his opponents and foreign critics, many Belarusians see the former collective farm manager as having brought stability after the uncertainty that followed the 1991 Soviet collapse. While the landlocked nation, about as big and flat as Kansas, is far from prosperous, the economy is growing and salaries are rising.

Critics say the economic successes are unsustainable, based largely on cheap Russian energy and heavy-handed state intervention reminiscent of the communist era.